Recycling options for used sandblasting grit into road construction 1 DANIELA LAURA BURUIANA, 1 MARIAN BORDEI, 2 IOANA DIACONESCU, 2 AUREL CIUREA 1 Faculty of Metallurgy, Materials Science and Environment 2 Faculty of Engineering “Dunarea de Jos” University of Galati 47, Domneasca Street, 800036, Galati, ROMANIA e-mail: [email protected], http://www.fmsm.ugal.ro Abstract: The grit is an abrasive blasting material used for the preparation of the metal surfaces in the ship building and ship repair processes prior the application of coatings. The waste is a spent grit used for sand blasting in the cleaning operations of tankers in the dock yard. This paper presents the modified properties (chemical composition, the shape and size of the particle) of the steel grit during the blasting process and the possibility of recycling the waste as a fine aggregate in the road construction industry. The management of solid waste from abrasive blasting is an issue which will be more frequently encountered in the future. While existing guidelines and regulations are available, a single resource which spans such a wide array of information does not currently exist. Future work should concentrate on collecting and summarizing best management practices for abrasive blast material (ABM) waste management in a format which could be used by the many industries which perform abrasive blasting, and the engineering and regulatory community. The recycling of spent sandblasting grit, commonly referred to as spent ABM, into asphalt concrete is investigated by the shipyard as an alternative to disposing the spent ABM in a landfill. Key-Words: abrasive blasting material, sandblasting grit, road, shipyard, ship building, repair process. 1 Introduction The naval industry is facing at the beginning of this century major problems. These appear not to be linked either to an eventual raw material resources or energetic crisis, or to the metallic materials competition with other materials, but they are rather linked to the acute demands of the environment protection. The development of the construction and naval repairing industry is conditioned by the major problems solving that come out of the industry nature relationship on the pollution control and natural and energetic resources protection. In the ship repairing area, there should be given up to the waste notion for the grit used for ship body sanding/blasting, more correctly being talked about by products. The preoccupations followed in the development strategies of the shipyards around the world go in two directions: - the development of superior technologies that substantially reduce emissions; - the growth in efficiency of the regaining and recycling of the by-products close to 100% values. The ecological concept applied to industrial systems engineering imply the development of these technological production processes with closed loop in which no resource is eliminated all the are continuously reused, no waste material or other product is evacuated in the environment that in the subject literature is found as “waste free industry” or “zero waste industry”. In the cleaning of the metallic surfaces of the ships, new or for fixing, there are used mixtures made of metallic pellets, grit (cast iron or steel) and natural sand (derived from natural or artificial rock grinding). After many usage cycles in the sanding operations, the material Recent Researches in Energy, Environment and Landscape Architecture ISBN: 978-1-61804-052-7 172
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Recycling options for used sandblasting grit into
road construction
1DANIELA LAURA BURUIANA,
1MARIAN BORDEI,
2IOANA DIACONESCU,
2AUREL CIUREA
1Faculty of Metallurgy, Materials Science and Environment
Abstract: The grit is an abrasive blasting material used for the preparation of the metal surfaces in the ship
building and ship repair processes prior the application of coatings. The waste is a spent grit used for sand
blasting in the cleaning operations of tankers in the dock yard. This paper presents the modified properties (chemical composition, the shape and size of the particle) of the steel grit during the blasting process and the
possibility of recycling the waste as a fine aggregate in the road construction industry. The management of solid waste from abrasive blasting is an issue which will be more frequently encountered in the future. While existing guidelines and regulations are available, a single resource which spans such a wide array of
information does not currently exist. Future work should concentrate on collecting and summarizing best management practices for abrasive blast material (ABM) waste management in a format which could be used
by the many industries which perform abrasive blasting, and the engineering and regulatory community. The recycling of spent sandblasting grit, commonly referred to as spent ABM, into asphalt concrete is investigated by the shipyard as an alternative to disposing the spent ABM in a landfill.
Fig. 1-4. EDAX analysis of the elements marked using a high energy surface that allows
in-depth view
The study highlights a very important issue for
the used grit recycling and that is the grit
composition doesn’t go through major
deviations from its initial state. The analyzed
waste has as main components Si and iron
oxides. The composition is similar to that which
is formed at hydraulic materials hardening. A
more rugged texture, characteristic to
aggregates, assures bigger adhesion forces
between aggregate granules and the binding
agent, an extremely important thing for road
concretes.
The fully automated ASAP Accelerated Surface
Area and Porosimetry System is designed for
high-performance/high sample throughput to
help today's busy laboratories expand their
workflow while providing highly accurate and
precise surface area and porosimetry
measurements. With six independently operated
analysis ports, a new analysis can begin as soon
as another is finished.
This provides an important advantage over
many multi-port instruments that require all
samples to be prepared or analyzed at the same
time. In addition, a key, standard feature of the
ASAP is a programmable and fully automated
sample preparation module with twelve
independently operated ports. Samples may be
added or removed from degas ports without
disturbing the treatment of other samples
undergoing preparation or analysis.
The term BET was derived from the first initials
of Burnauer, Emmett and Teller, and refers to
the method of measuring the surface area and
porosity of solid materials using the principals
of physical adsorption and de-sorption of gas.
The Micrometric's ASAP 2000 system has the
versatility to characterize samples using a
number of different adsorptive gases as
Nitrogen. In physical gas adsorption, an inert
gas, mostly nitrogen, is adsorbed on the surface
of a solid material.
This occurs on the outer surface and, in case of
porous materials, also on the surface of pores.
Most widely known is the determination of the
BET surface area by gas adsorption. Adsorption
of nitrogen at a temperature of 77 K leads to a
so-called adsorption isotherm, sometimes
referred to as BET isotherm, which is mostly
measured over porous materials
Recent Researches in Energy, Environment and Landscape Architecture
ISBN: 978-1-61804-052-7 176
Fig. 5. Analysis grit BET pore size
The ASAP 2000 measures high-resolution
adsorption isotherms on a wide range of
materials.
The interactive display allows users to zoom in
on the fine details of the isotherm. The
expanded graph shows the precise closure of the
adsorption and desorption isotherms.
The results of sample analysis device
sandblasting grit with ASAP 2000 surface area
and porosity using ASAP 2000 apparatus under
the guidance using Department of
Environmental Engineering and Chemical
Technology, Pannon University Hungary.
3. Recycling options for used sandblasting
grit into road construction
A better knowledge of leaching tests and
results, as well as of material properties, is very
important in the assessment of waste ABM for
use in road construction. The aim of this work
has been to investigate leaching of primary and
secondary road-making materials and study
factors that may have an influence on the
release of trace elements such as chromium,
zinc and manganese, magnesium that are
regarded as pollutants.
The main objective of the study is the
determination of the optimum between the grit composition and its grinding fineness.
The value of the resulted analyses values were
compared to those estimated in the quality
norms of aggregates, value decisively
influenced by factors which can be impurities
content, dimensional characteristics of the
granules and the physic-chemical
characteristics.
The results interpretation of the grit samples
show that the analyzed grit has physical and
chemical properties similar to standard analysis
of the sand used in asphalt composition:
- an angular granulation, unrounded
(considerably influences the concrete
resistance); - a silicon-aluminous composition
(the compounds are similar to those which are
formed at the construction materials hardening,
formed puzzolanic asphalt, mainly from
reactive silicon dioxide and aluminum oxide
which can contain other oxides too – iron
oxide).
The aimed general objective in used grit
capitalization process for asphaltic material
includes the production of a composite with
adequate physic-mechanic properties,
competitive and comparable with traditional
materials used in road asphalting domain:
- reduced connection capacity of the heavy
metals in watery environment;
- less quantities that doesn’t negatively affect
the connection and hardening properties of
heavy metals. Out of the materials used for road construction,
the grit waste can be classified at
hydraulic/puzzolanic binding agents, together
with sand and furnace slag.
Recent Researches in Energy, Environment and Landscape Architecture
ISBN: 978-1-61804-052-7 177
Table 4. Comparative results of the used abrasive blasting material [1, 4, 8, 10]
Bitumen 60/70 [84] Bonded
reinforcement Slow Cure
Composition % weight [1,8,10]
Large aggregate 10/20 30 30 30 - - -
Aggregate average 5/10 25 25 25 40 40 40
Used sandblasting grit [8] - - 13 - 12 12
sand 0/3 13 13 29 12 12 42
Chalk - 4 3 - 8 6
Cement 4 - - 7 - -
Bitumen 5 5 5 6 6 6
Granularity % weight [1]
Screening through ¾” 100 100 100 - - -
Screening through 1/2” 95.8 95.8 95.8 100 100 100
Screening through 3/8” 72.7 72.7 72.7 7.6 7.6 7.6
Screening through ¼” 57 57 57 78.3 78.3 78.3
Screening through mm 5 44.8 44.8 44.8 60.8 60.8 60.8
Characteristics [4]
Density of mix real [kg/dm3] 2.717 2.693 2.711 2.723 2.681 2.701
Specific gravity bitumen [kg/dm3]
1.025 1.025 1.025 1.025 1.025 1.025
Specific gravity conglomerate [kg/dm3]
2.519 2.499 2.514 2.490 2.456 2.477
4 Conclusions The paper presents the research results made for the
purpose of recycling options for used sandblasting grit in composite materials realization used into road
construction. The purpose of this research was to emphasize the possibility of recycling used grit was
an asphalt composition material, presenting the necessary grit granulation as well as the Si and iron oxides concentration necessary for the mixture used
in asphalting (asphaltic mixture) process. Looking for a way/method of using grit waste, the
propounded solution could be the large scale use of stabilized mixture technology (treated granular aggregate with puzzometric binding agents using
used grit), following the example of advanced countries (in our country the roads rehabilitation
problem needs big material, aggregate, binding materials consumption, difficult to be provided from traditional resources).
Conclusions conclude that theoretical and experimental research presented in the paper was
called for by the importance of recycling grit wastes. Proposals for using the material obtained from recycling of grit wastes in stabilized mixtures with
binders used in roads asphalt, the shipyard studied being able to benefit from economic advantages by
reducing costs allocated to the collection, transport and disposal grit wastes.
References:
[1] D. NegoiŃă (Buruiana), Contribution to the reduction of waste generated by shipyards” PhD
thesis, 2007. [2] Al-Sayed M. H., Madany I. M., Use of copper blasting grit waste in asphalt mixes in Bahrain,
Construction and Building Materials, Vol. 6, Issue
2, 1992, pp. 113-116.
[3] Amada S., Hirose T., Senda T., Quantitative evaluation of residual grits under angled blasting, Surface and Coatings Technology, Vol. 111,1999
[4] Gheorghe M., Valorificarea deşeurilor si subproduselor industriale în construcŃii, Ed.
MatrixRom, Bucuresti, 2004. [5] Henley, N, Spash, C., Cost-Benefit Analysis and the environment, UK, Edward Elgar Publishing
Ltd., Gower House Aldershot, 1993.
[6] Mandravel C., Stanescu R., Metode fizico
chimice aplicate la măsurarea noxelor in mediul
profesional, Ed. Academiei Române, Bucureşti,
2033, pp. 139-158.
[7] Mohammad Ismail M., Madany H.,
Raveendran Al-Sayed, Utilization of copper
blasting grit waste as a construction material,
Waste Management, Volume 11, Issues 1-2,
1991, pp. 35-40.
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